Tone-arm for phonographs.



R. J. PRETTIE.

rows ARM FOR PHONOGRAPHS.

APPLICATION FILED IULY 15. 1915.

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To all whom it may concern:

lie it known that l, RICHARD J. Pnnrrrn, a citizen of the United States, residing at Jamaica, in the county of Queens and-State of New York, have invente and useful improvements in Tone-Arms t'or Phonographs, of which. the following is a specification.

My present invention relates to an improved tone-arm for phonographs, talking machines, and the like, the structural. and operative advantages of which will be readily apparent to those skilled in. the art from an understanding of the following descrip tion in connection with the drawings.

in the drawings, Figure l is a fragmen tary vertical section of a talking machine showing my tone-arm in side elevation; Fig. 2 is an enlarged vertical section of the tonearm shown by itself; Fig. 3 is an enlarged end view looking at the sound-box and tonearm in Fig. 1 from the left side of said fig ure, the dotted lines showing the sound-box and the end tone-arm section swiveled into out-oiE-playing position; Fig. 4 is a section on the line 4 4: in Fig. 2 looking in the direction of the arrows; Fig. is an enlarged section, on the line the direction oi the arrows; and Fig. 6 is an enlarged detail of Fig. 2.

Describing now the specific devices of the drawings, certain of these represent merely the usual talking machine parts. Thus, 1 is the upper portion of the cabinet, 2 the lid, 3 the to shelf, 4: the motor spindle, 5 the turnta lo, and 6 the neck of the horn.

The tone-arm shown is made up of three sections,-an outer section 7, a middle sec tion 8, and an inner section 9, the sound-box 10 being attached to the outer section.

11 is a stationary vertical sleeve connectingthe tone-arm with the horn, and 12 is a horizontal flange by which said sleeve is secured to the small end 6 of the horn. A. circular seat or bottom 36 is provided in the upper end of the sleeve 11. Also a bearing pin 14 is pro vided concentric with said circular seat, said in being supported for vertical adjustment y a set screw 15 in the overhanging end oi extension 16 from the sleeve 11, and having a conical end 14* to coact with a conical hole in the boss 1! in the tone-arm. "The eonvexbottom 36 tends to heap the tone-arm centered on it's seat and specification. of Letters Patent.

certain new 55 in Fig." 2 looking in bearing 13 having a convexll atenterli lteb. lid, lhliltll. eerie] Ito. moan.

the conical end it permits any wear to be taken up by adjusting the pin 14 into a lower position.

The result is that inner section 9 of the tone arm is permittedrto swivel about a vertical axis coincident with the pin 14,as can also the tone-arm sections 7 and 8 and the sound-box, all being supported by or carried with said inner tone-arm section" 9.

The middle tonenrm section 8 is straight andis pivoted for vertical play to the section 9 by trunnion-screws 38. One end of said middle section fits into the mouth of the inner section 9 and both are spherically shaped so that the middle section can pivot up andv down on said trunnion-screws. These screws have a smooth shankportion adjacent the head received with rotary bearing fit in holes through the tone-arm section 9 (Fig. 5) and have an end shank portion which is reducednnd screwed into the wall ot' the middle tone-arm section reinforced by pieces 18 soldered or brazed thereto. The smooth shank portion is made a trifle longer than the hole through the tone-arm section 9 to permit section 8 to pivot freely on the section 9.

19 is a stop riveted to the under side of the middle tone-arm sectionvpositioned to bear against the mouth of the inner section, not when the soundhox is in playing position with the needle on the record as in Fig. l, but only when it has been swung, as will be hereafter explained, into the out-ot-playing position shown by the dotted lines in Fig. 3. w

The outer tone-arm section *2 is a horizontally disposed elbow. one limb thereoi being partly telcscoped into the forward end oi the middle section 8 and the other limb projecting laterally for connection with the sound-box 10. The wall of the first named limb has a slot 20 in which is located a projection 21 from the middle tone-arm section 8. The result is that the outer section 7 can be rotated about the longitudinal axis of the middle section 8 through an are equal to the length of the slot 20. Said slot is made of such length and is so positioned that the sound box 10 can be swung from the vertical position shown by the full lines (Fig. 3) up wardly into the dotted out-o'f-playing position wherein it is suptorted by the end of the aforesaid slot 20 bearing against the pro jection 21. llhe projection (Figs. 2 and tlii ill)

of said middle section. A leaf-spring as is secured to the middle section also by said screw 22, said spring bearing against the aforesaid washer 23, so that the wall of the.

middle section is clamped between said washer and the basal flange of the sleeve '23 whereby the projection 21 is strongly attached to the middle tone-arm section.

The referred to leaf-spring QAcarries a convex projection 25 (Fig. 2) at its free end, which it delivers inwardly through a hole in the middle section. 26 is a cuplike depression in the wall of the outer tonearm section 7 positioned so that the projection 25 snaps into it when the sections are in the playing position shown by the full lines in Figs. 1 and 3. The result is' that the outer and middle tone arm sections are thereby locked together and act like a single tube,first, in pivoting vertically about t e trunnions 38 when the sound-box rises and falls due to vertical inequalities in rotation of the record and turn-table; and secondly, in swinging horizontally across the face of the record along with the inner tone-arm section 9 as the latter swivels about the pin 14. The weight of the tone-arm is insuflicientlto overcome this spring catch 2526, and accordingly the parts remain locked together until the operator desires to lift the sound-box to change the record, whereupon he twists the end tone-arm section 7 and attached sound-box toward the left or dotted position in Fig. 3, the initial twisting'pres sure causing the projection 25 to ride out of the depression 26, thereby overcoming the spring catch and permitting the parts to be twisted over into the dotted non-playing position. At this time the previously described stop 19 comes into action by pre venting the sound-box and outer part of the tone-arm from pivoting downwardly below the position wherein said stop strikes against the mouth of the inner tone-arm section 9.

The sound-box 1.0 is also of novel construction and being claimed elsewhere need not be described here, other than to say that it has a tubular neck having a pin, the neck telescoping into the mouth of the outer tonearm section (Fig. 3) with the pin received into a slot or notch in said month, said pin and notch both being positioned to give the needle 30 (Fig. l) the desired or proper inclination to the record.

Finally, referring to Fig. 4, 31 is a pin projecting from the stationary arm 16; and it acts as a stop limiting the swin of the tone-arm in both directions by coacting with the spaced pins 32 projecting on the same level from the elbow 9.

Having thus described my invention, what I claim is:

l. A tone arm comprising tubular sections one of which is adapted to carry a sound box, the adj acent ends of said sections being relatively rotatable about the axis of the sections as a center, one of said section's having a circumfcrcntihl recess corresponding in length to the angle of relative rotation of the sections and also having a depression, a sleeve fitted in the other section, a plate having a portion to engage in said depression and thus hold the sound box carrying section in a predetermined. position against rotation, and. a screw operative to secure said sleeve and plate together and to the respective section and having a portion projecting into said circumferential recess to limit the angle of relative rotation of the sections.

2. A tone arm comprising tubular sections one of which is adapted to carry a sound box, an end of one section fitting telescopically and rotatably within the other section, one of said sections having a circumferential recess and also a depression, a ietractile member having a part arranged to engage in said depression and thereby hold the sections at a predetermined angle of rotation, and a screw operative to secure said member to the respective section of the tone arm and having a portion projecting into said circumferential recess to limit the angle of relative rotation of the sections.

3. A tone arm comprising tubular sections one of which is adapted to carry a sound box, an end of one section fitting telescopically and rotatably within the other section, one of said sections having a circumferential seat and also a. depression, a sleeve fitted into the wall of the other section, a spring plate having a projection arranged to coiiperate with said depression to hold said sections at a predetermined point against rotation, and a screw operative to secure said sleeve and spring plate together and to the respective section, said screw having a portion projecting into said circumferential seat to limit the angle of relative rotation and to prevent relative longitudinal movement of. the sections.

4. A tone-arm comprising two tubular sections, one of said sections being rotatable within the other, means for limiting said rotation comprising a recess on the one part and a pin in said recess on the other part, said pin being the end of a screw tapped into a flanged sleeve which projects outwardly through a hole in the outside tonearm section, the projecting outer end of the sleeve being. surrounded by a washer which is forced by the head of the screw into wmm with said mmwiurm sizctiun so than;

saiii sectiun is dammed-l hetwezen said: was m nd the flanged pol-"10m 0:? 121m ah-awe 5. A. tone-mm cmn'pmsmg; Wm tubular sec pm hair; .dhe end 0f .ascreW mpped. inw a flanged sleeve, which projects outardly through a, hole in the 'outside toneav'rm section, the projecting unisex end; of the slmave being surrounded by a Waher which cnnmc'zwilth am gmd aectwn 1s ciampfiol bewmen smd Washer aforesaid scrmv, said 5pm :cm, the wther "mm-mm sec'timn, Whiifh latter "is thererewss ad to arecaiva a pro jmtian 0n the spring. 1 Y

is famed, by the lmemdl 01E? QZGEWW mm bu-1w. m smciymn am that and the flanged part-ion m5 n'zhea shave; and a lemfisprmg secumd mm" '11? he mad the pmqmm adyw In testlmany wltlemvmf I have signed my name to thig speaificmtian, this 14; day 0.1?

July, 1915.

I JMCHMEVD PE-QETTEIE. 

